| Fred, has been rapidly intensifying during the last 24hrs. This is a clear example, of favorable upper air conditions versus a hostile environment further west. As I stated on a previous thread, slightly below normal SST's across areas of the basin and a weak el nino or .08 degrees above normal was not enough to hinder Fred from strengthening to a Cat 3 cane. I wouldn't be surprised if he reached CAT 4 status tonight, Even in the far eastern atlantic. Where african waves in this region find themselves struggling to intensify. This is mostly due to strong easterly shear and borderline SST's. Even with extremely low end OHC, he was able to obtain Major status and the main factor being an excellent upper air pattern (High Pressure Aloft) and light shear. As has been the case this season, mid-upper level shear will increase over the system and induce weaking with a decease in SST's north of 20. I don't think el nino is at levels to over take the basin as in 2009, we have seen much stronger one's in previous years 1992,1997,2001. As with any el nino some reduction in the number of storms will occur, just not at the levels we've seen this year. I will attempt to find the reason why such an unfavorable pattern has evolved this year. Note: One possible cause in the shear, is an early winter pattern. In the upper plains, ohio vally and northeast, temps have averaged below normal. A Long wave pattern amplifies during the summer and shortens during the winter. Short wave lengths increases deep layer troughs and cold upper level low's. In turn it reduces large scale ridging, which allow larger areas of light shear across the basin in favored genesis in the tropical atlantic. A good example, is Fred having a small window of opportunity, because by tomorrow a deep layer trough will increase shear. See Link below and click OHC to view. http://cimss.ssec.wisc.edu/tropic2/real-time/storm.php?&basin=atlantic&sname=07L&zoom=4&img=1&vars=11111000000000000000000&loop=0 |